yuval-js-2.js

const arbitraryDataList = [{
		rootId: 'false'
	},
	{
		root: {
			field1: 'val1'
		}
	},
	{
		root: {
			field2: 'val2'
		}
	},
	{
		root2: {
			field2: 'val2'
		}
	},
	{
		root2: {
			field2: 'val2',
			fieldaaaa: {
				fielda: 'valaaaa'
			}
		}
	}
];

const reduceListToJSObject = (someList) => someList.reduce((accumulator, currentValue, currentIndex, array) => {
	const rootKeys = Object.keys(currentValue);

	console.log(currentValue);

	if (rootKeys.length > 0) {
		for (let i = 0; i < rootKeys.length; i++) {
			const currentKeyVal = rootKeys[i];
			const value = currentValue[rootKeys[i]];

			const currentKey = rootKeys[i];
			console.log(value);
			console.log('typof key ===>', typeof value);
			console.log('currentKey ===>', currentKey);

			switch (typeof value) {
				case 'string':
					accumulator[currentKey] = value;
					//   return accumulator;
					console.log('accumulator ===>', accumulator);
					break;

				case 'object':
					// do something;
					if (accumulator.hasOwnProperty(currentKey)) {
						console.log('i have this key already: ', currentKey);
						console.log('time to merge');
						console.log('accumulator[currentKey] ===>', accumulator[currentKey]);
						console.log('value :', value);
						const mergedObj = {
							...accumulator[currentKey],
							...value
						};
						console.log('mergedObj ===>', mergedObj);

						accumulator[currentKey] = mergedObj;
					} else {
						accumulator[currentKey] = value;
					}
					console.log('accumulator ===>', accumulator);

					break;
			}
		}
	}
	console.log(accumulator);

	return accumulator;
}, {});

const expectedOutput = reduceListToJSObject(arbitraryDataList);
console.log('expectedOutput ===>', expectedOutput);

const obj1 = {
	a: 'a',
	b: 'b'
};
const obj2 = {
	c: 'c',
	a: 'yuval'
};
//   const newObj = Object.assign({}, obj1, obj2);
const newObj = { ...obj1,
	...obj2
};
console.log('newObj ===>', newObj);